The New York State attorney general is cracking down on supplements sold at Target, Walmart, GNC, and Walgreens. A study found that four out of five supplements do not contain the ingredient on the label.

It may come as a shock to the tens of millions of Americans who buy herbal supplements to find out that their “ginseng” is nothing more than powdered garlic and rice.

On Monday, the New York State attorney general’s office sent cease-and-desist letters to four major supplement retailers, including Target, GNC, Walgreens, and Walmart after discovering that four out of five tested supplement products did not contain any of the herbs on their labels. The New York Times reported that many of the "medicinal herb" pills contained little more than cheap fillers, such as powdered rice, asparagus, and houseplants.

About 50 percent of Americans take supplements, annually investing about $28 billion, according to the University of California, Berkeley. A 2013 study from the Canadian Institutes of Health Research estimated there are about 65,000 dietary supplements on the market consumed by more than 150 million Americans, according to the Associated Press, creating a lucrative industry.

"Mislabeling, contamination and false advertising are illegal," said Eric T. Schneiderman, the state attorney general, reported the New York Times. "They also pose unacceptable risks to New York families — especially those with allergies to hidden ingredients."

While supplement labels are misleading consumers, they also are putting consumers in compromising situations. For example, Walmart’s ginkgo biloba supplement contained mostly powdered radish, houseplants, and wheat, despite a label claiming it as wheat and gluten-free. Unlisted fillers were also present in GNC brands, including powdered legumes, which fall into the class of plants (which also includes peanuts and soybeans) that are may be hazardous for those diagnosed with allergies.

The investigation included the testing of 78 bottles of the leading brands of herbal supplements from the four retail chains across New York State. An agency analyzed the products – including ginkgo biloba, St. John’s wort, ginseng, garlic, echinacea, saw palmetto, and valerian root – using the same DNA process used to discover labeling fraud in the seafood industry.

The testing was performed by DNA bar coding experts from Clarkson University in Potsdam, N.Y. They tested three to four samples of each of the supplements purchased, and each sample was tested five times. Overall, 390 tests involving 78 samples were performed, according to NewsmaxHealth.com. Only 21 percent of test results verified DNA from plants listed on the labels. Walmart showed only 4 percent.

"This investigation makes one thing abundantly clear: The old adage 'buyer beware' may be especially true for consumers of herbal supplements," Schneiderman said, reported the Associated Press. He demanded companies provide detailed information on processing, production, quality control, and testing for supplements sold at their stores.

Dr. Pieter Cohen, an assistant professor at Harvard Medical School and an expert on supplement safety, aired his concerns about the attorney general’s extreme test results. He said they were hard to accept and that it was possible they had failed to detect some of the plants found in the supplements. Regardless, the study has major implications.

"If this data is accurate, then it is an unbelievably devastating indictment of the industry," said Dr. Cohen, reported the New York Times.

In a statement, Walgreens spokesperson James Graham announced they will be removing these products from their shelves nationwide until they conduct the necessary research. Walmart spokesperson Brian Nick stated they are immediately reaching out to suppliers to take appropriate action. GNC spokesperson Laura Brophy said they will cooperate with the attorney general’s office, but that they still stand by "the quality, purity, and potency of all ingredients listed on the labels of [their] private label products." Target has yet to release a statement.

Whatever comes of this situation, the attorney general’s office has shed light on regulation deficiencies and needed improvement when it comes to labeling ingredients on supplement labels.

"The absence of DNA does not explain the high percentage of contaminants found in these products," said Marty Mack, an executive deputy attorney general in New York, reported the New York Times. "The burden is now with the industry to prove what is in these supplements."